1. Field of the Invention
The embodiments discussed herein are directed to socket connectors, and more particularly to a socket connector supporting high-speed transmission used to electrically connect circuit boards in communication devices.
2. Description of the Related Art
Communication devices contain a backplane and multiple daughter boards arranged side by side on the backplane at right angles thereto. The backplane has plug connectors mounted thereon. The daughter boards have socket connectors provided at their respective ends. The daughter boards are electrically connected to the backplane by connecting their socket connectors to the corresponding plug connectors.
Recent years have seen increases in signal transmission speed, and differential transmission has often been adopted as a method of signal transmission. This causes socket connectors to be configured to support differential transmission. For example, socket connectors have pairs of contacts for plus signal transmission and minus signal transmission, and also incorporate shield members.
Conventional socket connectors have contact modules and shield members alternately and closely arranged and incorporated in a housing.
Since the contact modules and shield members are closely arranged and incorporated, their rear portions project on the rear side of the housing. Since the rear portions of the contact modules thus project on the rear side of the housing, it is desirable that the contact modules be in sufficiently stable alignment in their assembled state. This is because if one or more of the contact modules come out from the housing during handling such as transportation to disorder their alignment, the contact modules may have to be realigned at the time of mounting the socket connectors on the daughter boards.
According to a conventional socket connector, multiple triangular recesses are formed side by side on the end faces of the rearward projecting parts of a housing, and wedged projections are formed on contact modules. The wedged projections of the contact modules are fitted into the corresponding triangular recesses so that the contact modules are positioned. Further, the contact modules are fixed to the housing with their respective bulge parts. (See, for example, Japanese Laid-Open Patent Application [Japanese translation of PCT international application] No. 2003-529909.)
Conventionally, the contact modules are fixed to the housing with their respective bulge parts, and the shield members are coupled and fixed to the contact modules. The shield members, however, are not fixed to the housing. Accordingly, prevention of the coming-out of the contact modules relies on the strength of their own fixation.
Further, the upper projections of the contact modules are fitted into the corresponding recesses on the end face of the upper projecting part and the lower projections of the contact modules are fitted into the corresponding recesses on the end face of the lower projecting part, so that the contact modules are positioned. Therefore, if the contact modules come out rearward, even if only slightly, from the housing, the contact modules become unrestricted to get loose easily, so that their positions become unstable.
Therefore, it is necessary to handle assembled socket connectors and mount the socket connectors on daughter boards with deliberation.